1. Field of the Invention
The present invention relates to a coating composition applied onto the surface of floor covering for retention of surface gloss, a floor surface-coated body coated therewith and a process for producing the same, as well as a composite film for forming a resin coating film excellent in gloss retention.
2. Description of the Prior Art
As floor covering in fast-food stores, convenience stores, department stores, gymnasiums, hospitals, offices, houses, factories etc., there are used i) resinous tiles and sheets such as vinyl chloride etc., ii) wooden materials such as wooden flooring, iii) ceramic materials such as porcelain tiles, iv) stone materials such as marble, and v) concrete materials such as mortar.
These kinds of floor covering can be used as such, but are usually coated with a polishing agent such as wax etc. for preventing surface deterioration, improving durability, and conferring gloss and non-slip properties. Further, the applicant proposed an invention of an aqueous coating for floor surface in order to reduce the cumbersome daily operation for floor maintenance by coating with a polishing agent or the operation of removing a polishing agent (Japanese Patent Application No. 248703/1996), as well as a composite film making the coating operation itself unnecessary (Japanese Patent Application No. 254347/1997).
However, even if the conventional aqueous coating for floor surface or the composite film described above is used, the floor surface gloss in a store is deteriorated in a few months after coating. Further, dirt including earth and sand, edible oils such as lard and process oils contained in a rubber sole of a shoe adheres to the floor surface and is remarkable. There are many cases where like a coating layer of a conventional polishing agent, the coating film should be removed.
In view of these problems in the prior art, the object of the present invention is to provide a coating composition for the surface of floor covering, by which the deterioration of surface gloss caused by walking thereon hardly occurs, colored dirty resulting from lard, process oils etc. is minimized and the colored dirty can be easily removed by e.g. polishing, a floor surface-coated body coated therewith and a process for producing the same, as well as a composite film capable of forming a resin coating film excellent in gloss retention.
The present invention relates to a coating composition applied onto the surface of floor covering, comprising a photo-curing oligomer and a photo-initiator wherein the average number of functional groups per molecule of the photo-curing oligomer is 4 or more.
The present invention was made on the basis of the new finding that the average number of functional groups per molecule of the photo-curing oligomer is related to the gloss retention performance of a coating film formed by curing said coating composition.
That is, in the present invention, the average number of functional groups per molecule of the photo-curing oligomer contained in the coating composition is 4 or more. The coating composition is applied onto the surface of floor covering, and upon irradiation with light, is linked and cured by the photo-initiator. A coating film capable of preventing deterioration of gloss is thereby formed on the surface of the floor covering.
Accordingly, the coating film formed from the coating composition of this invention hardly undergoes the deterioration of surface gloss by walking thereon and is excellent in the gloss retention performance. Further, colored dirty attributable to lard, process oils etc. is not remarkable.
The dirty on the coating film can be easily removed by e.g. polishing, and thus the operation of refreshing the surface of floor covering is easy. Removal of the coating film is also feasible or a coating film can also be formed thereon. It is also possible to repair flaws in the coating film.
Further, the daily cleaning method may be a very simple method. For example, the gloss of the surface of floor covering is restored by cleaning the coating film with a duster cloth, a dust-collecting brush or a suction-type cleaner, or by wiping it with a mop containing water or a neutral detergent. Accordingly, daily cleaning by a mechanical method using a polisher, a vanisher etc. is unnecessary, thus achieving a significant reduction in the maintenance cost.
Further, dirt adhering to the surface of the coating film can be easily removed by polishing it with a sand paper, an abrasive-containing compound or a cleanser, and so on. However, depending on a polishing method, there is the case where after removal of dirt by polishing, buffing should be conducted to restore the gloss.
That is, the coating film formed from the coating composition of this invention leads to a significant reduction in the total cost for floor maintenance.
According to the present invention, there can be provided a coating composition for the surface of floor covering, by which the deterioration of surface gloss caused by walking thereon hardly occurs, colored dirty resulting from lard, process oils etc. is minimized and the colored dirty can be easily removed by e.g. polishing, a floor surface-coated body coated therewith and a process for producing the same, as well as a composite film capable of forming a resin coating film excellent in gloss retention.
FIG. 1 is a characteristic graph showing the relationship between the average number of functional groups per molecule of the photo-curing oligomer and the gloss retention performance of the coating film in Example 1.
FIG. 2 is a characteristic graph showing the relationship between the average number of functional groups per molecule of the photo-curing oligomer and the gloss retention performance of the coating film in Example 2.
FIG. 3 is a characteristic graph showing the relationship between the average number of functional groups per molecule of the photo-curing oligomer and the gloss retention performance of the coating film in Example 3.